This is one of those data structures with a misleading name. Throw out the hashing part. It's not part of the data structure, it's just one use case. When you do that, you discover that this structure is something between a trie and a B+ tree. It's a persistent data structure for indexing fixed-size bit patterns to arbitrary values, with node sizes that aim for a compromise between update (copy) speed and lookup speed (number of pointers chased before reaching the value).

It's cool, but don't tell yourself it's only good for hashing.